This textbook covers knowledge in the endocrine sciences. Each chapter is structured to cover both established concepts and newer developments. The chapters blend basic science with essential elements of clinical knowledge in order to give students an appreciation of the consequences of deranged endocrine function. This 4th Edition presents the latest advances in energy metabolism, obesity and the control of appetite, interactions between the immune and endocrine systmes and their implication for tumor growth, hypothalamic peptides involved in the regulation of pituitary function, fluid and electrolyte balance, hormones of the heart and brain and the series of factors that regulate gonadal, adrenal and thyroid development and function. The two chapters on the rapidly evolving fields of genes and hormones and sexual differentiation have been completely rewritten by new authors. This book is intended for medical students taking physiology and advanced undergraduate students taking physiology and basic endocrinology courses.